The current construction of signaling lamps allows for the control of light by employing multiple lenses, including a first converging lens and a second diffusing lens (see FIG. 1). For example, U.S. Pat. No. 5,947,587, which is incorporated by reference herein, discloses a signal lamp comprising a box-shaped housing 1 having an open end 2 that is closed by a spreading window 3. LEDs 4 are clustered around a central axis 6 of the housing 1 and a positive lens 7, which is described as a fresnel lens, is interposed between the spreading window and the LEDs.
LEDs 4 are disposed in an array having a surface area that is 25% of the surface area of the Fresnel lens 7. The Fresnel lens 7 acts to converge the light beam pattern and then the spreading window 3 diffuses the light. Using two optical elements, i.e., the Fresnel lens and the spreading window, results in light loss through the two optical components. Furthermore, two separate optical components are required to be manufactured and assembled into the signal lamp, adding to the manufacturing cost and efficiency of the LED signal.
Accordingly, it is desirable to develop an efficient signaling lamp that diffuses the light before converging the light so as to control the distribution of light onto the field, while using less plastic parts.